The present invention relates to a method of finishing a gear with a gear finishing tool having a gear-type or rack-type finishing teeth.
Japanese Patent Publication No. 58-54935 discloses a gear finishing method in which backlash or play is provided between tooth surfaces of a finishing tool and those of a workpiece gear to be finished by the tool. According to the disclosed gear finishing method, the gear is finished by driving the finishing tool and allowing the gear to follow the finishing tool, or vice versa, or by switching the directions of rotation of the finishing tool and the gear. However, this prior method cannot finish the gear to a high accuracy since the tooth surfaces of the finishing tool and the gear as they rotate in mesh with each other slip at irregular speeds and also since their teeth tend to hit each other due to the backlash. For gaining a cutting or grinding speed required to finish the gear efficiently, it is necessary to rotate the finishing tool and the gear at considerably high speeds while they are meshing with each other. High-speed rotation however disturbs desired dynamic balancing, resulting in a reduced finishing accuracy. In addition, any apparatus designed to carry out the above conventional method is structurally complex because of the required ability to drive the finishing tool and allow the workpiece to follow the finishing tool, or vice versa, or switch the directions of rotation of the finishing tool and the workpiece gear.
The present invention has been made in an attempt to solve the problems and deficiencies with the prior gear finishing method.